textproduct: Albany

WHAT HAS CHANGED

Lowered NBM dewpoints on Thursday to be more in line with most other sources of guidance. Also increased wind gusts Thursday, as a strong cyclone is expected to track northeast through the St. Lawrence Valley.

KEY MESSAGES

1) Continued comfortable and dry weather will continue through tonight. Some showers and thunderstorms are expected Wednesday.

2) A strong area of low pressure passing by to the north will bring windy conditions for Thursday, along with the potential for strong thunderstorms.

DISCUSSION

KEY MESSAGE 1...

A weak area of surface high pressure over the region today will gradually shift east off the New England coast tonight into early Wednesday. Other than a few diurnally driven showers popping up in the Adirondacks this afternoon, it will remain dry through tonight. The dry air mass and mainly clear skies will result in another cool night with lows in the upper 40s to mid 50s. A warm front approaching from the south/west will bring increasing clouds and scattered to numerous showers on Wed, and perhaps a few T-storms. Modest instability forecast with SBCAPE generally 500 J/Kg of less, so threat for any severe storms is very low Wed.

KEY MESSAGE 2...

Chances for showers will increase after midnight Wed night, as a potent short wave aloft approaches from the Great Lakes, with a deepening cyclone tracking into SE Ontario. Complex setup for Thu, as the warm sector associated with the system looks muddled due to a pre-frontal trough expected to result in fairly widespread showers and a few T-storms Thu morning. This is when PWATs will be highest too, as deeper moisture starts to decrease Thu afternoon. Also, there is a notable mid level cap (~500 mb) evident in forecast soundings Thu P.M. So while there will be strong forcing from the sub-990mb cyclone and very high magnitude of 0-6 km wind shear of 50-70 kt, it is questionable if there will be enough moisture and buoyancy to balance the strong shear. The Storm Prediction Center has a Marginal Risk (level 1 of 5) for severe storms for much of the area except a Slight Risk (level 2 of 5) from around Poughkeepsie south. This seems reasonable given potential for more overlap between instability/shear in southern areas.

Due to the strength of the anomalously deep cyclone (MSLP anomalies of -3 to -4 STDEV) tracking NE through the St. Lawrence Valley Thu, south-southwest winds will increase considerably. v-component(southerly) wind speed anomalies of +3 to +4 STDEV are also forecast from the NAEFS. Blended in 90th percentile NBM winds for Thu, which results in peak gusts of 25-35 mph, but could be even higher in some spots. Will continue to monitor trends. These speeds could result in some sporadic downed tree/branches, especially with leaves on the trees this time of year.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR conditions are expected through at least this evening, with just occasional cloud patches 5000-7000 FT AGL. Most areas should remain VFR tonight into Wednesday morning, however can not completely rule out a bit of patchy fog at KGFL and KPSF, especially if skies remain clear long enough. Brief periods of IFR/LIFR could occur if any fog develops. Isolated/scattered rain showers may develop at KGFL and KALB between 16Z-18Z/Wed, accompanied by brief MVFR Vsbys.

West to northwest winds 5-10 KT this afternoon will become light/variable tonight, then trend into the south at 5-10 KT by late Wednesday morning.

Wednesday Night: High Operational Impact. Breezy. Definite SHRA. Thursday: High Operational Impact. Windy With Gusts To 33 kts. Definite SHRA...TSRA. Thursday Night: Low Operational Impact. NO SIG WX. Friday: Low Operational Impact. Breezy. NO SIG WX. Friday Night: Low Operational Impact. Breezy. NO SIG WX. Saturday: Low Operational Impact. Breezy. Slight Chance of SHRA...TSRA. Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Breezy. Slight Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.